Performing a suspension fork oil change on your Fox 34 AWL is a key maintenance procedure that ensures consistent damping performance, improved small bump sensitivity, and overall longevity of the fork. Whether you’re a seasoned road cyclist venturing onto gravel paths or an all-road enthusiast, knowing how to carry out this service correctly is essential.
This guide will walk you through the process, from tools and setup to oil replacement, reassembly, and final testing. All steps and information apply specifically to the Fox 34 AWL model and should not be generalized to other Fox fork lines or suspension types.
Tools Required
- Torque wrench [paid link] (in Nm)
- 10mm and 15mm sockets
- 2mm and 5mm hex keys [paid link]
- Oil syringe (for measured oil input)
- Measuring cylinder (graduated)
- Clean microfiber cloths
- Suspension-specific grease (e.g., Fox Float Fluid or Slickoleum)
- Suspension oil: Fox 20wt Gold or as specified for Fox 34 AWL
- Clean workspace or maintenance stand
- Nitrile gloves
- Drain pan
- Soft mallet (optional)
Preparation and Safety
Before starting, it is critical to depressurize the air spring. Open the air cap and release all air from the fork using a shock pump with a bleed valve. Remove the front wheel and brake caliper to prevent damage during the service. The Fox 34 AWL should be clamped using a fork-specific stand to maintain orientation during draining and reassembly.
Removing the Lowers
To begin the oil change:
- Remove the rebound knob from the right leg using a 2mm hex key. Carefully place it aside.
- Using the appropriate socket (typically 10mm or 15mm), loosen the foot nuts on both fork legs. Do not remove them entirely yet.
- Lightly tap the nuts with a soft mallet or socket driver to break the internal seal between the lower legs and the damper/air shafts.
- Once unseated, remove the foot nuts and allow residual oil to drain fully into a prepared pan.
- Slide the lowers off carefully and inspect the dust wipers for wear or contamination. Clean thoroughly using a dry microfiber cloth.
Cleaning and Inspection
With the lowers removed:
- Inspect the inside of the stanchions for scoring or oil residue buildup.
- Clean the lower leg internals with a lint-free cloth. Do not use degreasers or harsh cleaners.
- Check the foam rings and replace them if they show signs of hardening or excessive contamination.
- If reusing the same dust wipers, ensure they are clean and re-lubricated before reassembly.
Replacing Suspension Oil
The Fox 34 AWL requires specific oil volumes in each leg:
- Damper leg (right): Approx. 40ml of 20wt Gold
- Air spring leg (left): Approx. 10ml of 20wt Gold
Using a measuring cylinder or oil syringe, fill each side through the fork lowers before reinstallation. Apply suspension grease to the foam rings and wiper seals for smooth reengagement.
Reinstalling the Lowers
Slide the fork lowers gently back onto the stanchions. Ensure even and controlled movement to avoid damaging the seals or misaligning the bushings.
Once seated:
- Thread the foot nuts onto the damper and air shaft bolts.
- Torque each to the manufacturer’s specification (typically around 5.65 Nm).
- Reinstall the rebound knob and ensure full adjustability through its range.
Air Spring Recharging and Testing
After reassembly:
- Inflate the air spring to the recommended pressure based on rider weight and intended use.
- Cycle the fork a few times by compressing it fully to distribute the oil and check for consistent damping.
- Listen for unusual sounds such as squelching or hissing, which may indicate an oil underfill or trapped air.
Troubleshooting Set-Up Issues
Common problems after an oil change include:
- Excessive noise or cavitation: May signal insufficient oil or improper bleed during shaft reseating.
- Harsh top-out or bottom-out: Check oil volumes and inspect the air spring for correct inflation.
- Leaking from seals: Dust wipers may be incorrectly seated or overfilled with grease. Re-clean and reapply with the correct amount of lubricant.
Proper oil fill and torque application eliminate most performance inconsistencies after a service.
Performance Optimization and Customization
The Fox 34 AWL is built for riders who demand a balance of stiffness and sensitivity on mixed terrain. To fine-tune performance:
- Adjust oil viscosity within Fox’s recommended range if prioritizing small bump sensitivity or damper support.
- Consider upgrading to low-friction seals for smoother initial stroke response.
- Add volume spacers to the air spring for a more progressive spring rate suited to aggressive descents or bikepacking loads.
These customizations should be made only after confirming the baseline setup is functioning as intended post-oil change.
Model Comparison
The Fox 34 AWL is often compared with the Fox 34 Rhythm and Fox Performance lines. While sharing chassis dimensions, the AWL is optimized for all-weather and light trail/gravel conditions:
- AWL vs. Rhythm: AWL has a broader temperature range and smoother factory tune for road-oriented mixed terrain.
- AWL vs. Performance: The Performance model features GRIP dampers with more adjustability but is overbuilt for most road-gravel applications.
Understanding these distinctions helps riders choose based on terrain, ride style, and upgrade potential.
Component Compatibility
The Fox 34 AWL is designed to integrate with a wide range of modern road and gravel setups:
- Axle standard: 15x110mm Boost
- Steerer: Tapered 1.5″ to 1 1/8″
- Brake mount: Post-mount for 160mm to 203mm rotors
- Compatible with 29″ wheels and tires up to 2.4”
Ensure headset, rotor, and axle interfaces match these specifications during installation.
FAQs
How often should I change the oil in my Fox 34 AWL fork?
Oil should be changed every 50 riding hours or at least twice per season for consistent performance and longevity.
Can I use different oil weights in the Fox 34 AWL?
Only use oils recommended by Fox, such as 20wt Gold. Altering viscosity may affect damping and void warranties.
Is it necessary to remove the air spring during an oil change?
No, unless you are also servicing the air spring. Standard oil changes do not require air spring disassembly.
What torque spec should I use for the foot nuts?
Fox recommends torquing the foot nuts to approximately 5.65 Nm for the AWL model.
What signs indicate it’s time for an oil change?
Reduced fork responsiveness, inconsistent rebound, and oil leakage are clear indicators of service need.
Can I upgrade the damper in the Fox 34 AWL?
Upgrades are limited due to chassis and damper compatibility. Consult Fox’s technical documents before considering swaps.